 /*******************************************************************************
  * Copyright (c) 2000, 2006 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.ui.dialogs;

 /**
  * For validating selections in some selection dialogs.
  * <p>
  * Clients should implement this interface to define specialized selection
  * validators.
  * </p>
  */
 public interface ISelectionValidator {
     /**
      * Returns a string indicating whether the given selection is valid. If the
      * result is <code>null</code>, the selection is considered to be valid; if the result is
      * non-empty, it contains the error message to be displayed to the user.
      *
      * @param selection the selection to be validated
      * @return the error message, or <code>null</code> indicating
      * that the value is valid
      */
     public String isValid(Object selection);
 }

